With the ever-increasing industrial demand for high energy density lithium-ion batteries, lithium-rich manganese-based layered oxide cathodes have attracted much attention due to their high specific capacity and low cost. However, their practical application is hindered by critical drawbacks including low initial Coulombic efficiency, irreversible oxygen release, and severe voltage fade. In this paper, bulk-engineered lithium-rich manganese-based layered oxides with a full concentration gradient were prepared by a room-temperature ammonia plasma interfacial modification strategy. In contrast to direct ammonia sintering, ammonia plasma modification could construct a stable spinel-amorphous composite nano-bifunctional motif ordered interface on the cathode surface that endowed fast Li⁺ transport kinetics. This bulk-surface functional motif ordering design concept could provide a novel and effective strategy for improving the overall electrochemical performance of lithium-rich oxide cathodes.

A precursor of cobalt-free full-concentration gradient twin-domain lithium-rich manganese-based layered oxide cathode material was synthesized by a co-precipitation method. After washing for impurity removal and vacuum drying, the precursor was uniformly mixed with 3% (in mole fraction) excess Li₂CO₃ for lithium supplementation and sintered to prepare the cobalt-free gradient lithium-rich manganese-based layered oxide cathode material (GLLOs). To investigate the modification effects of different treatment methods under ammonia atmosphere, the equal mass of GLLOs was subjected to direct ammonia sintering and ammonia plasma modification, respectively. The crystal structure, micro-morphology, electrochemical performance, ion transport kinetics, and transition metal valence state evolution of the materials before and after modification were determined by systematic characterizations including X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, electrochemical measurements, and kinetic analysis, respectively. Furthermore, the regulatory differences of ammonia treatment in different states on the performance of GLLOs and their intrinsic action mechanisms were revealed.

Two distinct ammonia-based treatments (i.e., direct ammonia sintering and ammonia plasma technology) have different impacts on the GLLOs' surface structure, valence variation, electrochemical performance, and stability. Direct ammonia sintering forms a rock salt-amorphous interface with more significant Mn valence reduction, improving initial efficiency and rate capability, while degrading cycling stability. Ammonia plasma constructs a stable spinel-amorphous interface facilitating Li⁺transport, with a milder Mn valence change, effectively stabilizing interfacial reactions and structure to remarkably enhance long-cycle performance and mitigate voltage decay.

The formation of rock salt and spinel phase functional units on GLLOs surface stems from ammonia-induced TM valence reduction, triggering Li leaching, oxygen vacancy formation, and TM migration to Li layers that drive layered-to-spinel/rock salt transformation. Direct ammonia sintering requires prolonged heating with limited ammonia decomposition, most nitrogen intermediates adsorb on the material surface, causing excessive TM migration and a rock salt-N-rich amorphous interface. Ammonia plasma enables a rapid ammonia decomposition into nitrogen intermediates for quick modification, forming a spinel-amorphous interface that enhances Li⁺ transport, inhibits oxygen loss, electrolyte corrosion, and stabilizes cycling via short-time treatment.

In this work, twin-domain lithium-rich manganese-based layered oxide cathodes with bulk full-concentration gradient were interface-modified via direct ammonia sintering and ammonia plasma treatment. The effect of interface modification method on the surface structure, electrochemical performance, TMs valence, kinetics, and stability was investigated. Ammonia nitridation could form a 2-3 nm N-containing amorphous interface, alleviating oxygen vacancies and enhancing oxygen redox reversibility. Ammonia plasma, operating at room temperature for minutes, could decompose into nitrogen active species under high electric field, constructing a spinel-amorphous composite interface favorable for Li⁺ transport. It could avoid Mn over-reduction and spinel-to-rock salt transformation, maintaining TMs reversibility. A robust bulk-surface synergistic stabilization system was established via integrating the bulk full concentration gradient twin-domain design with the surface composite nano-bifunctional motif ordering construction, remarkably boosting the electrochemical performance of the cathodes (i.e., the capacity retention of 81.5% after 900 cycles at 1 C, accompanied by a low voltage decay of only 0.21 mV/cycle). Controllable ammonia decomposition could facilitate a stable interface formation, offering a novel pathway to boost the comprehensive performance of LLOs.

Terahertz (THz) waves, typically spanning the frequency range from 0.1 to 10 THz, possess unique characteristics such as low photon energy, broad bandwidth, and strong penetration through nonpolar materials, enabling important applications in wireless communication, biomedical sensing, and nondestructive evaluation. Efficient manipulation of the amplitude, frequency, and phase of THz radiation is essential for the development of high-performance functional devices. Metasurfaces composed of subwavelength artificial meta-atoms provide a versatile platform for THz wavefront engineering through tailored electromagnetic responses. However, most reported THz metasurfaces operate in the linear regime and rely on propagation or geometric phase, which limits their functionality to the fundamental frequency and prevents the integration of frequency conversion and wavefront control. Second-harmonic generation (SHG) offers an effective approach for extending the accessible THz spectral range. Conventional nonlinear crystals, however, suffer from low nonlinear efficiency and stringent phase-matching requirements in this frequency region, which restrict device miniaturization and integration. Resonant artificial microstructures in semiconductors provide an alternative nonlinear mechanism through strong local electromagnetic field enhancement, where the Lorentz-force-driven nonlinear current gives rise to an effective second-order response. Nevertheless, the phase of nonlinear radiation remains difficult to control independently of the radiation amplitude. Therefore, establishing a deterministic relationship between the resonance phase and the nonlinear radiation phase is critical for nonlinear wavefront engineering. In this work, a GaAs-based metasurface is designed to correlate the resonance phase at the fundamental frequency with the phase of the second-harmonic radiation, enabling phase-engineered nonlinear wavefront construction.

The metasurface consists of gold split-ring resonators patterned on a silicon-doped n-type GaAs epitaxial layer grown on a semi-insulating GaAs substrate. Under normal incidence of an x-polarized THz wave, the resonant current in the metallic ring generates a localized magnetic field perpendicular to the surface and a strongly enhanced electric field in the split gap. The electric field drives free carriers in the n-GaAs layer, while the localized magnetic field exerts a Lorentz force on the moving carriers, resulting in a nonlinear current oscillating at twice the fundamental frequency. Three-dimensional full-wave simulations based on the finite-element method were carried out to optimize the structural parameters and analyze both the linear resonance and nonlinear time-domain response. An anisotropic conductivity tensor was introduced to describe the magneto-electric coupling induced by the Lorentz force. Four meta-atoms with equally spaced resonance phases were designed, and an additional π phase shift was obtained by rotating the structures by 180°, resulting in eight discrete nonlinear phase states covering the full 0-2π range. The samples were fabricated using metal-organic chemical vapor deposition, photolithography, magnetron sputtering, and lift-off processes. The nonlinear response was characterized using a home-built strong-field terahertz time-domain spectroscopy (THz-TDS) system, in which the second-harmonic signal was extracted by spectral filtering and detected via electro-optic sampling.

Frequency-domain simulations show that all metasurface structures exhibit pronounced resonances near 0.8 THz, ensuring that the nonlinear phase comparison is performed under nearly identical linear response conditions. At the resonance frequency, strong local electric and magnetic field enhancements are observed, providing the physical origin for the Lorentz-force-driven nonlinear current. Time-domain simulations and experimental measurements confirm the generation of a cross-polarized second-harmonic signal at 1.6 THz. The four designed meta-atoms provide a phase interval of 0.25π, and the corresponding rotated structures introduce an additional π phase shift, resulting in eight discrete nonlinear phase states with nearly uniform spacing over the entire 0-2π range. Although slight amplitude variations exist among different unit cells, the measured phase evolution follows the designed linear dependence, indicating that the nonlinear phase can be effectively modulated through the resonance phase. Based on the experimentally extracted complex responses of the meta-atoms, an equivalent surface current model was employed to reconstruct the far-field radiation. By arranging the discrete phase elements according to the helical phase distribution, the reconstructed far-field exhibits a doughnut-shaped intensity profile and a continuous azimuthal phase variation of 2πl, which are the characteristic features of vortex beams. These results confirm that the experimentally obtained nonlinear phase library enables nonlinear helical wavefront construction through ordered spatial arrangement of the meta-atoms.

A nonlinear metasurface capable of phase-engineered terahertz second-harmonic radiation has been designed and experimentally demonstrated. By correlating the resonance phase at the fundamental frequency with the phase of nonlinear radiation, eight discrete nonlinear phase states covering the full 0-2π range were achieved through meta-atom design and structural rotation. Based on the experimentally extracted complex responses, nonlinear helical wavefronts were reconstructed through ordered spatial arrangement of the phase elements. The results verify that nonlinear wavefront engineering can be achieved through the cooperative strategy of meta-atom design and ordered arrangement. This approach enables the integration of frequency conversion and wavefront shaping within a planar artificial structure and provides a feasible route for phase engineering in nonlinear THz metasurfaces as well as for integrated structured-light sources in THz communication, imaging, and information processing.

Power splitters with low loss, compact footprint, and high stability are essential building blocks in modern on-chip photonic integrated systems for optical interconnection, signal routing, and dynamic optical power management. Conventional on-chip power splitters rely on phase matching and modal interference, and therefore usually suffer from splitting-ratio drift, increased loss, and enhanced crosstalk under bandwidth dispersion, fabrication errors, and bending-induced defects, making it difficult to maintain stable and consistent performance in large-scale integration. Photonic topological insulators (PTIs) exhibit remarkable advantages in suppressing backscattering, tolerating sharp bends, and maintaining robustness against defects due to their unique topologically protected edge-state transport, thus providing an effective route for the design of high-performance power splitters. However, the existing topological power splitters still regulate the splitting ratio via modifying geometric parameters, reconfiguring topological interfaces, or changing the coupling path length, so continuous dynamic tuning within a fixed structure remains difficult after fabrication, which restricts their application in reconfigurable integrated photonic systems. To overcome this limitation, this work was to propose a liquid-crystal-assisted topological power splitter based on coupled valley photonic crystal waveguides. From the perspective of functional units and ordered architectures, the device used petal-shaped VPC unit cells as the functional units and utilized zigzag topological interfaces together with backward-coupled waveguides as the ordered splitter architecture, thereby enabling continuously tunable power distribution through external-field-controlled liquid-crystal molecular reorientation, while preserving topological robustness.

A petal-shaped VPC unit cell was designed as a functional unit of the device. The spatial inversion symmetry was broken and a topolo gical bandgap was opened under transverse-magnetic (TM) polarization via changing the rotation angle from α of 0° to α of ±30°. Two topologically distinct domains (denoted as VPCA and VPCB) were then arranged into zigzag AB and BA interfaces, forming an ordered architecture that could support valley-locked edge states. On this basis, a topological power splitter consisting of two parallel topological waveguides and one rectangular coupling region was constructed. The coupling distance (d) was 4a and the coupling length (L) was 170a. A nematic liquid crystal (LC) was introduced into the air holes in the boundary waveguide and coupling regions. A line source polarized along the out-of-plane direction was placed at Port 1 to excite the edge state in WG1. The numerical simulations were conducted to calculate band structures, projected interface bands, transmission spectra, power-flow distributions, and electric-field distributions. In the numerical model, the liquid crystal was treated as a uniaxial anisotropic medium, and its optical response was described by an orientation-dependent permittivity tensor associated with director rotation in the XZ plane. The ordinary and extraordinary refractive indices were taken as n_o of 1.45 and n_e of 1.75, respectively. The LC-controlled section length was denoted by w, and its influence on the output power ratio was investigated at a fixed operating frequency of 193.4 THz. To evaluate topological robustness, six defects belonging to three representative defect types were introduced into the structure.

Based on this mechanism, effective backward coupling is realized between two adjacent topological waveguides in opposite propagation directions, and the simulated power-flow distribution shows a coupling loop consisting of forward transport in WG1, backward transport in WG2, and local vortex-mediated energy flow. To verify whether the coupling effect can be still preserved after introducing liquid crystal (LC), the transmission spectra of the two cases without and with LC filling in the boundary-waveguide and coupling regions are compared. The results show that effective coupling maintains in both cases, while the operating frequency range shifts after introducing LC. In the LC-filled case, nearly complete power transfer from WG1 to WG2 is achieved at 193.1-193.6 THz, and the total transmission efficiency reaches 93% as L=170a. When the LC orientation changes fromθ of 90° to θ of 0°, the coupling band shifts from 192.5-194.1 THz to 185.8-187.2 THz. At a fixed operating frequency of 193.4 THz, increasing the LC-controlled length w continuously reduces the effective coupling region, decreases the output power from WG2, and increases the transmitted power in WG1, thereby enabling continuously tunable power splitting in a fixed structure. In addition, the transmission spectra and output power ratios remain nearly unchanged under the representative defect types, defect numbers, and defect distributions, indicating that the proposed device maintains a good robustness against structural perturbations.

An LC-assisted topological power splitter based on coupled valley photonic crystal waveguides was proposed and numerically demonstrated from the perspective of functional-unit engineering and ordered-architecture design. The device could achieve robust edge-state transport, effective inter-waveguide coupling, and continuously tunable power distribution within a fixed structure via combining petal-shaped valley photonic crystal unit cells, zigzag topological interfaces, the ordered architecture of backward-coupled waveguides, and external-field-controlled molecular reorientation of nematic liquid crystal. The results showed that the proposed splitter could reach a total transmission efficiency of 93%, realize continuously tunable power splitting via adjusting the LC-controlled length, and maintain stable transmission and power-distribution performance under the representative defect conditions. This work could provide a feasible strategy for reconfigurable on-chip power routing, dynamic optical interconnection, and actively tunable topological photonic devices.

Although the aforementioned technologies continue to be optimized along their respective development paths, there remain insurmountable bottlenecks. There is an inherent trade-off between consistency, control precision, and production efficiency. When pursuing high precision and high consistency, production efficiency is often compromised (e.g., by using slower scanning speeds or finer layer-by-layer stacking), whereas pursuing high-speed production tends to result in reduced structural controllability (e.g., excessively fast laser scanning leading to uneven pore morphology, or excessively fast template-based molding causing disordered pore orientation). This 'engineering trilemma' represents the core contradiction that thick electrode manufacturing technologies must address as they transition from the laboratory to large-scale production. Overall, there is currently no single technology capable of simultaneously achieving high precision, high consistency, and high production efficiency. Future breakthroughs may lie in: 1) the integration of multiple technologies, such as combining rapid laser processing with the template method—first using a template to construct a macro-porous framework, then employing lasers for localized fine-tuning. 2) Process innovation, including the development of continuous ice-templating or roll-to-roll compatible guided forming processes. 3) Equipment upgrades, such as the development of new equipment for multi-beam parallel laser processing and high-speed multi-nozzle 3D printing. Therefore, identifying a scalable manufacturing technology that integrates all three elements is key to transitioning thick electrodes from laboratory research to large-scale application.

Research on thick lithium-ion battery electrodes is currently at a critical stage of development. As a bridge linking intrinsic properties at the atomic scale to macroscopic performance at the electrode scale, the rational assembly of unit cell structures will become a core technological pathway for next-generation high-energy/high-power batteries. Achieving this goal requires addressing numerous challenges, including gaining a deep understanding of transport mechanisms, enabling the controlled synthesis of electrode structures, and ensuring compatibility with existing battery manufacturing systems. The engineering of unit cell structures offers us a new research direction and a broader perspective.

As a highly promising filtering component for next-generation lightweight and miniaturized electronic circuits, supercapacitors have pursued performance breakthroughs centered on the synergistic optimization of ultrafast frequency response and high areal capacitance. Reviewing the evolution of electrode design for filtering supercapacitors reveals a paradigm shift from mere compositional engineering toward an ordering-driven paradigm guided by rational microstructural design. In this review, carbon-based filtering electrodes are systematically categorized according to structural dimensionality and spatial organization, including two-dimensional planar architectures, three-dimensional randomly macroporous frameworks, and highly vertically aligned configurations, thereby elucidating a pivotal role of structural ordering in governing charge-transport kinetics. In particular, three-dimensional ordered grid electrodes constructed from carbon tubes as functional building units are identified as an effective strategy to resolve the intrinsic trade-off between capacitance density and frequency response.

From the construction of an integrated electron/ion transport networks, the systematic structural evolution clearly demonstrates that the continuous improvement of filtering supercapacitor performance does not arise merely from the unbounded enlargement of specific surface area, but rather from achieving an optimal balance between ion transport accessibility (i.e., low-tortuosity pathways) and interfacial charge-storage density (i.e., highly active surfaces). Such carbon-tube-based, ordered interconnected networks extend the performance limits in terms of capacitance and frequency response, and provide a robust and reproducible structural framework for ultrafast charge transport, thereby effectively propelling the transition of supercapacitors from conventional energy-storage devices toward high-frequency filtering applications.

Despite the remarkable potential of functional unit ordering strategies, some substantial challenges remain in translating this concept toward deeper theoretical understanding and practical implementation. From a theoretical perspective, there is an urgent need to establish a universal, quantitative descriptor system for assessing the "degree of ordering" in electrode architectures. Specifically, key geometric descriptors should include tortuosity (i.e., quantifying deviation of ion transport pathways from ideal straight channels), connectivity parameters (i.e., lateral junction density), orientation distributions (i.e., reflecting alignment along the current collector normal), and spatial uniformity metrics. The quantitative relationships can be established between structural parameters and kinetic metrics such as phase angle, cutoff frequency, and characteristic time constants via integrating these descriptors with electrochemical impedance spectroscopy and multiphysics simulations. Such a framework linking geometric descriptors to dynamic electrochemical responses will enable a transition from empirical optimization toward digitally guided electrode design.

In terms of transport mechanism analysis, it is particularly important to develop methods capable of decoupling the respective contributions of electronic conduction and ionic diffusion. For instance, an experimental strategy involving "fixed structure-variable conductivity" can be employed, whereby the crystallinity of the material is selectively tuned, while maintaining identical three-dimensional architectures and mass loading, thereby isolating the influence of electronic transport on the frequency response. In parallel, finite element simulations based on realistic structural models with independent variation of electronic conductivity (σ_e) and ionic diffusivity (D_ion) can be used to perform sensitivity analyses and establish causal relationships among structure, transport parameters, and electrochemical performance. These methods provide a critical theoretical guidance for the targeted optimization of ordered electrode architectures.

At the structural design level, future efforts should focus on maintaining kinetic advantages under thick-electrode and high-mass-loading conditions. To mitigate the transport limitations caused via increased loading, strategies such as constructing multidimensionally interconnected networks and optimizing hierarchical pore size distributions are required to ensure ultralow transport resistance for both electrons and ions, even in the deep regions of electrodes. This is essential for achieving simultaneous enhancement of areal capacitance and frequency response.

From an engineering perspective, the scalable fabrication of large-area, highly uniform ordered electrodes remains a key bottleneck in practical applications. Future developments should aim at synthesis strategies with improved generality and process tolerance to enable a smooth transition from centimeter-scale laboratory samples to industrial-scale electrode systems. In addition, some challenges relating to device packaging and circuit integration must be addressed, including minimizing the resistance at electrode/current collector interface, suppressing parasitic effects under high-frequency operation, and optimizing impedance characteristics at target frequencies (e.g., 120 Hz and above). Furthermore, the structural stability of three-dimensional porous architectures under long-term cycling, electro-thermal coupling, and mechanical deformation, as well as the reliability of multi-device integration, will critically determine their feasibility in applications.

Overall, building-unit ordering represents not merely a structural optimization strategy, but a unifying paradigm that bridges materials design, device performance, and application scenarios. With continued advancement of multiscale structural regulation capabilities, in-situ characterization techniques, and theoretical modeling tools, a research on filtering supercapacitor electrodes is expected to evolve from empirically driven exploration toward mechanism-informed and quantitatively guided design, ultimately enabling a broad application in highly integrated and miniaturized electronic systems.

The strategy of "functional building block architecture" has a promising potential in the preparation of high-performance carbon-like materials (such as graphite, boron nitride, and their composites). High-performance carbon-like materials are successfully fabricated via architecting various functional building blocks (such as onion carbon and onion boron nitride), achieving substantial improvements in the performance. This strategy provides an effective pathway for the development of next-generation high-performance carbon-like materials. The functional building block architecture strategy offers a novel paradigm for tailoring the properties of carbon-like materials, exhibiting broad prospects for development. Future research should involve: 1) the synergistic architecture of multiple types of functional building blocks to achieve multifunctional integrated material design; 2) combining computational simulations with artificial intelligence for high-throughput screening and optimization of functional building block combinations and architecture methods; 3) extending the application of this strategy to more extreme service conditions, such as high temperature, high pressure, and irradiation environments; and 4) advancing the controllable preparation and large-scale application of architected materials to promote the engineering application of carbon-like materials in high-tech fields such as aerospace, electronic devices, and nuclear energy.

This review systematically summarizes the structure-performance relationships of supported metal catalysts for CO₂RR from the perspective of structural ordering of active functional units. It is emphasized that catalytic reactions are governed by localized active centers rather than the overall catalyst structure. The spatial arrangement, coordination environment, and electronic properties of single-atom, dual-atom, and nanoparticle sites collectively determine the adsorption and transformation of key intermediates (e.g., *COOH and *CO), thereby regulating activity, selectivity, and stability. In different functional units, a unified understanding emerges. The catalytic performance is dictated by the synergistic coupling between geometric configuration and electronic structure. Single-atom sites enable a precise electronic regulation through coordination engineering, dual-atom sites introduce metal-metal coupling and cooperative effects that can break scaling relationships, and nanoparticle sites provide multi-site platforms governed by size, facet, and interface effects. These multilevel interactions construct a complex yet systematic structure-performance network. Furthermore, the paradigm of catalyst design shifts from empirical trial-and-error approaches to data-driven strategies. Machine learning methods, including descriptor-based models and machine learning potentials, significantly improve the efficiency of catalyst screening and enable the exploration of large configurational spaces and dynamic structural evolution. The integration of theoretical calculations, machine learning, and experimental studies accelerates the transition toward rational catalyst design.

Despite substantial progress, several key challenges remain in the rational design of CO₂RR catalysts. First, active sites often undergo dynamic reconstruction under realistic electrochemical conditions, while most of the existing studies rely on static models. Developing simulation methods that incorporate potential, solvent, and interface effects, together with advanced in-situ characterization techniques, is essential for identifying true active structures. Second, the lack of a unified multiscale framework limits the understanding of how atomic-scale electronic structures translate into macroscopic catalytic performance. Bridging this gap requires establishing quantitative relationships across multiple scales, from electronic structure and local geometry to interfacial properties and mass transport processes. Finally, a predictive capability of machine learning models is still constrained by descriptor selection and data quality. Developing physically interpretable descriptors and constructing high-quality datasets, combined with strategies such as active learning and transfer learning, will be crucial to improving model generalization and applicability.

Overall, the transition from "experimental observation with theoretical interpretation" to "theory-guided prediction with experimental validation," as well as from "global structural optimization" to the "precise regulation of structural ordering of functional units," represents a key trend in the development of supported metal catalysts. In the future, a precise regulation of complex multi-electron reaction pathways is expected to be achieved via the synergistic design of geometric and electronic structures and the deep integration of theoretical calculations, machine learning, and advanced characterization techniques, providing a more robust theoretical and material foundation for CO₂ utilization and sustainable energy conversion.

In summary, atomically ordered catalysts represent a transformative platform for advancing NO₃RR from empirically driven material exploration toward mechanism oriented and structure defined catalyst design. This approach enables more rigorous elucidation of relationships between structure and catalytic performance via establishing well defined and identifiable active centers, thereby enhancing the reproducibility, comparability, and transferability of catalytic insights. More importantly, such systems provide an opportunity to bridge fundamental descriptors, adsorption energetics, and reaction pathways, offering a unified basis for rational catalyst design. Despite these advances, several critical challenges remain. In particular, the dynamic evolution of active sites under realistic electrochemical conditions, including surface reconstruction and adsorbate induced structural changes, remains insufficiently understood. In addition, the intrinsic complexity of multi-intermediate reaction networks poses significant challenges for identifying reliable descriptors and key elementary steps. The persistent gap between model catalysts and practical systems, especially in terms of long-term stability, mass transport, and operating current density, further limits the translation of fundamental insights into real world applications. Addressing these challenges will require the integration of precise atomic level design with advanced operando characterization techniques and data driven methodologies, enabling the capture of dynamic catalytic processes and the accelerated discovery of excellent materials. The convergence of atomic scale structural engineering, mechanistic understanding, and system level optimization is expected to play a pivotal role in enabling efficient, selective, and scalable NO₃RR technologies, ultimately contributing to the realization of a sustainable electrochemical nitrogen cycle.

This review introduces recent progress on the field of VEH based on ATIs. It respectively introduces VEH implemented in airborne sound and elastic wave systems based on topological edge states. VEH is realized due to the field enhancement effects induced by zero-dimensional localized states such as higher-order topological corner states and BICs. The multi-modal collaborative energy harvesting mechanisms oriente toward broadband and multi-frequency responses, further extending to high-throughput VEH based on large-area topological interface states. These studies demonstrate that ATI-based systems exhibit remarkable design flexibility, while maintaining both high energy conversion efficiency and strong robustness. The topological rainbow trapping effect is excited and the bandwidth limitations of conventional devices are overcome via introducing strategies such as structural modulation and multimodal coupling. On this basis, large-area topological waveguide states are used to substantially enhance energy transmission throughput, ultimately achieving comprehensive performance optimization in terms of high efficiency, broad bandwidth, and large capacity. However, the existing research on ATI-based VEH still has several limitations. First, the existing studies mainly focus on the medium- and high-frequency range, whereas low-frequency (≤100 Hz) VEH remains largely at the stage of theoretical exploration. The vibrations in everyday environments are predominantly low-frequency, a further research on low-frequency energy harvesting is still needed. Second, the evaluation of energy conversion efficiency in this field still lacks a unified standard framework. The electrical output metrics reported in previous studies, such as maximum voltage, output power, or amplification factor, are constrained via differing experimental testing benchmarks and therefore cannot be directly compared, which remains one of the key challenges to be addressed in the future VEH research. Meanwhile, most of the existing devices are still at the proof-of-concept stage and remain some distance away from practical engineering implementation and industrial application. Although topological states provide a relatively robust platform for energy transport, the existing studies on the stability of energy harvesting systems are still largely limited to structural defects and geometric perturbations. Systematic investigations into the effects of real environmental factors (i.e., temperature, humidity, load variation, and long-term operating conditions) on the performance of topological structures are still lacking.

At present, large-scale homogeneous fabrication of multi-level ordered structures remains challenging, and it is difficult to maintain structural integrity and ordering consistency during mass production. Long-term service performance in high-salinity, oily and complex actual water environments lacks systematic verification, and problems such as salt deposition, pore blockage and interfacial fouling easily cause performance degradation. In addition, most porous ordered materials exhibit insufficient mechanical toughness against water scouring and dry-wet cyclic aging, while the mismatch between high evaporation capacity and limited condensation efficiency has become a prominent system-level constraint. Corresponding future research directions are proposed as, advancing the diversification of functional units to construct multi-mechanism photothermal libraries; innovating diversified ordered configurations by learning from natural bionic structures; realizing controllable assembly of third-level macroscopic ordered architectures. At the same time, future studies should address engineering bottlenecks such as scalable preparation, long-term stability and mechanical durability, and fully exploit photothermally induced kinetic enhancement effects to expand application scenarios in high-salinity wastewater, oily sewage, sludge dehydration and radioactive water purification. This review systematically clarifies the regulation mechanism of multi-level ordered structures in energy conversion and mass transport, summarizes existing challenges and future development paths, and provides solid theoretical support and rational design guidance for the development of high-efficiency, stable and engineerable photothermal evaporation materials and decentralized water resource allocation systems.

This review systematically compares the mechanical properties and deformation mechanisms of LNT and GNT Cu to elucidate the quantitative effect of ordering strategy on the performance. Gradient ordering can provide greater extra strengthening and work hardening than laminated ordering, leading to a superior strength-ductility synergy. The underlying mechanism is rooted in the distinct distribution of plastic strain gradients and GNDs, while laminated ordering leads to GND accumulation at interfaces, gradient ordering promotes their dispersion throughout all the sections. These dispersed GNDs contribute to stronger strengthening and work hardening via enhanced back stress generation.

Despite recent advances on unit-ordering metallic materials, systematic research on their structure-property relationships and associated mechanisms remains in its early stages. This is particularly true for establishing design criteria for unit-ordering strategies that optimize the performance including strength, ductility, fatigue and fracture resistance, considering the complicated ordering and unit parameters such as ordering way, structural gradient, ordering sequence, unit type and their proportions. More importantly, it remains a challenge to fully understand the deformation mechanism of unit ordering metals, especially in the long-range inter-constraint across sections, which plays an important role in producing the deformation carriers for gradient deformation and extra strengthening. It is encouraged to combine experimental characterization, simulation, and mechanics modelling to address the key issues above.

Centered on structural design of organic functional crystals and starting from the fundamentals of spin dynamics, this review represents key spin-relaxation mechanisms in organic materials, including SOC, exchange interaction, and HFI, and summarizes representative spin-related phenomena such as organic magnetic-field effects, spin transport, and organic magnetism. On this basis, this review highlights how crystal order, polymorphism, molecular packing, and conformational differences regulate spin behavior, and summarizes how isotope effects, atom substitution, and cooperative interactions in multicomponent systems affect spin effects. Meanwhile, this review introduces spin behaviors at heterojunction interfaces and the physical mechanisms of chirality-induced spin selectivity in chiral materials, together with commonly used strategies for constructing chiral structures. Effective regulation of spin effects in organic functional crystals relies on coordinated advances in structural design, chemical-composition control, and device-structure optimization. Future studies should place a greater emphasis on the quantitative characterization of structural parameters, discriminative verification of spin-relaxation mechanisms, and statistical reliability in multicomponent and interfacial systems. It is expected to realize efficient and stable organic spintronic devices via integrating molecular design, crystal engineering, interface modulation, and device-structure optimization, supporting flexible electronics and low-power information devices as well as emerging spin-functional integration.

Although substantial progress is achieved, several important challenges still limit a broader implementation of patterned MOFs. First, the existing methods are material-specific and depend on MOFs containing radiation-sensitive ligands or specially designed functional groups, which restricts universality across the large MOF family. Second, the mechanisms of structural evolution under irradiation or localized processing remain insufficiently understood, particularly regarding changes in crystallinity, pore structure, surface chemistry, and transport properties. Third, an inherent trade-off still exists between ultimate resolution and scalable, high-throughput manufacturing. Techniques with nano-sized precision are often slow and costly, whereas more scalable approaches usually sacrifice pattern fidelity. Future research should therefore focus on designing process-compatible and radiation-responsive MOFs, developing stable colloidal and thin-film platforms, clarifying structure-property relationships during patterning, and combining top-down lithography with bottom-up selective growth. Progress along these directions is expected to accelerate the transformation of MOFs from high-performance porous materials into programmable micro-/nano-building blocks for next-generation integrated devices.

Lithium-ion and sodium-ion batteries underpin portable electronics, electric vehicles, and grid-scale energy storage. Their performance and safety are strongly constrained by cathode behavior, and practical screening repeatedly requires three types of predictions, i.e., voltage profiles during (de)intercalation, alkali-ion migration kinetics, and thermal stability against oxygen release and decomposition. Density functional theory (DFT) can provide accurate baselines, but its cost limits supercell sizes, configuration sampling, and the time/length scales accessible to ab initio molecular dynamics (AIMD). Pretrained machine-learning interatomic potentials (MLIPs) offer near-DFT accuracy at far lower cost, thus enabling high-throughput evaluation and long-time molecular dynamics. However, the fidelity required for voltage thermodynamics, migration kinetics, and high-temperature decomposition is not identical, and a model that performs well on one task may be unreliable on another. In this study, eight representative pretrained MLIPs (i.e., MACE, M3GNet, CHGNet, ALIGNN, SevenNet, AlphaNet, GRACE, and Orb) were systematically benchmarked across these three cathode-relevant tasks under matched protocols.

All crystallographic prototypes were obtained from the Materials Project. All the MLIPs were used as released pretrained models without fine-tuning to reflect a "drop-in" screening scenario. For voltage profiles, four representative cathodes spanning layered oxides and polyanion frameworks were selected, i.e., NaMnO₂, LiCoO₂, NaFePO₄, and Na₃V₂(PO₄)₃. Each parent structure was expanded to a supercell containing 8-12 alkali sites. Partially (de)intercalated configurations were generated by exhaustive enumeration of alkali-vacancy patterns and symmetry-deduplicated with a space-group analysis tool. Each MLIP evaluated energies for all configurations. Formation energies were referenced to alkali-rich/poor endmembers, and lower convex hulls were constructed to obtain piecewise average voltages. Accuracy and curve-shape fidelity were quantified using metrics including mean absolute error (MAE), root mean square error (RMSE), integrated absolute error (IAE), and bias indicators.

For ion migration, Li₃Sc₂(PO₄)₃ was chosen as a representative fast-ion conductor. Molecular dynamics was performed at 600 K for 2 ns with each MLIP, and the Li self-diffusion coefficient was extracted from the mean-square displacement (MSD) via the Einstein relation in three dimensions. A fixed regression window (200-1500 ps) was applied consistently to reduce transient and finite-sampling effects.

For thermal stability, oxygen-release/decomposition was benchmarked on phosphate systems with clear stepwise pathways, i.e., MnPO₄ and FePO₄ in olivine and trigonal polymorphs. Each step was represented by balanced solid-state reactions with explicit O₂ release. Reaction energies from MLIPs were combined with an ideal-gas oxygen chemical potential in an oxygen grand-potential framework to estimate onset temperatures and cumulative O₂-evolution curves.

The benchmark reveals a pronounced task dependence among pretrained MLIPs. For voltage profiles, most models reproduce the qualitative multi-plateau behavior, yet quantitative accuracy differs because voltages are sensitive to small energy differences among near-degenerate vacancy orderings that determine convex-hull vertices and plateau boundaries. Across the four cathodes, M3GNet achieves the minimum overall voltage error with a small systematic bias, followed by AlphaNet and CHGNet. GRACE is generally mid-tier, whereas Orb and ALIGNN exhibit larger offsets and shape errors. A notable system dependence occurs for LiCoO₂, where most MLIPs tend to underestimate voltages relative to the reference, indicating that layered Co-O chemistry remains a challenging regime for the existing universal pretrained models.

For ion migration in Li₃Sc₂(PO₄)₃ at 600 K, the ranking differs from the voltage benchmark. MACE and SevenNet yield diffusivities closest to the reference, with Orb and GRACE moderately higher. CHGNet and M3GNet overestimate a diffusivity by severalfold, while AlphaNet underestimates it more strongly. Importantly, ALIGNN can not reliably complete the long-timescale molecular-dynamics runs under our resource constraints, highlighting a practical limitation (memory footprint) that can matter in screening pipelines. These support the interpretation that diffusion is governed primarily by local force accuracy and barrier-region smoothness along hopping pathways, whereas voltage profiles depend on consistent ranking of many competing configurations across composition.

For thermal stability, all the MLIPs qualitatively reproduce the existence of stepwise oxygen evolution and pyrophosphate-forming decomposition, but predicted onset temperatures can deviate substantially. For MnPO₄, deviations span a wide range. ALIGNN and M3GNet provide the smallest deviations for this system, while AlphaNet and CHGNet delay oxygen release. Across the full phosphate set, M3GNet and MACE deliver the optimum overall agreement with experimental step positions and temperatures, and GRACE often captures intermediate steps with moderate errors. The results indicate that generalization to high-temperature, oxygen-deficient pathways remains sensitive to both training coverage and architectural bias.

This work established a unified, extensible benchmark for comparing pretrained MLIPs on cathode-relevant thermodynamics, kinetics, and high-temperature stability. No single MLIP could be universally optimal. M3GNet was most reliable for voltage prediction on the tested cathodes, MACE and SevenNet were strongest for long-time MSD-based diffusion in Li₃Sc₂(PO₄)₃, and M3GNet together with MACE best captured oxygen-release/decomposition trends in representative phosphate systems. The proposed workflow could provide a practical guidance for task-aware MLIP selection and a foundation for larger, more decoupled benchmarks in future studies.

As functional ceramics are increasingly required for more advanced device platforms and harsher service environments, the demand for even higher levels of performance continues to grow. At the core of this challenge lies the persistent coexistence of multi-objective trade-offs and multi-scale problems. Therefore, we systematically summarize the paradigm shifts and representative advances brought about by the introduction of AI into materials research. We outline the broader landscape of AI-enabled functional ceramics research from the perspectives of data, model and application, and further summarize the key strategies and transformative pathways for this field through three major directions: intelligent inverse design, cross-scale intelligent computation and large-language-model-driven research platforms. As data infrastructure, model capability and closed-loop deployment technologies continue to mature, artificial intelligence is poised to evolve from an auxiliary analytical tool into a systematic design framework that connects knowledge, computation, decision and experimental execution, thereby advancing functional ceramics research towards a more efficient and scalable paradigm.

MFMs decisively evolve from auxiliary computational tools into core engines for end-to-end intelligent R&D. They offer a unifying framework for the longstanding inverse design problem, enabling a systematic search of the MGI guided by target performance. Nevertheless, several challenges must be overcome to realize their full potential. Key limitations include the data scarcity for novel or extreme-condition materials, a need for even stricter integration of physical laws to ensure causal reasoning beyond correlation, and a "black-box" interpretability issue that can hinder trust in critical applications. Future development must focus on creating models with intrinsic causal reasoning capabilities, moving from statistical prediction to understanding the underlying mechanism of material features. This will be coupled with the integration of MFMs into fully autonomous laboratory platforms, where real-time perception from in-situ characterization and robotic control will enable closed-loop, self-driving experimentation. Ultimately, the convergence of AI and materials science steers a field from task automation toward high-level cognitive intelligence. This transition promises to fundamentally disrupt a conventional design logic, accelerating the discovery and deployment of advanced materials and ushering in a novel era of intelligent materials genome engineering.

AI achieves notable progress in polymer functional materials, particularly in inverse design, performance prediction, and process optimization, accelerating the shift from experience-driven to data-driven research. To fully unlock AI's potential, some challenges in data, algorithms, and integration must be systematically addressed. This review represents a dedicated polymer database, a functional unit-based encoding method, and an interpretable structure-performance framework to bridge the gap between "black-box" model outputs and human-understandable chemical insight. Four key directions for future work should be concerned, i.e., 1) building comprehensive, open, and interoperable polymer databases; 2) advancing generative and reinforcement learning for autonomous material discovery; 3) strengthening the dynamic coupling between experiments and models to form self-driving research loops; and 4) fostering interdisciplinary collaboration and integrated platform development. AI can evolve from a supportive tool into a core innovative engine for polymer functional materials, powered by the synergy of data, algorithms and experiments.

Proton-conducting solid oxide fuel cells (H-SOFCs) require highly active oxygen electrodes to enhance their electrochemical performance and stability at intermediate and low temperatures. However, conventional oxygen electrode materials often suffer from high thermal expansion coefficients and insufficient catalytic activity at reduced temperatures, making them unsuitable for H-SOFC applications. Misfit-layered oxides (MLOs) can offer a promising solution due to their unique structural and catalytic properties. In this study, a series of Na_0.15X_2.85Co₄O_9-δ (X=Ca, Sr, Ba; abbreviated as NCC, NSC, and NBC) materials were synthesized by a glycine-nitrate combustion method. These materials possess a misfit-layered structure ([X₂CoO_3-δ] and [CoO_2-δ] layers), which reduces their thermal expansion coefficients and enhances the catalytic activity of oxygen electrodes at intermediate and low temperatures. Among the Na_0.15X_2.85Co₄O_9-δ materials, NSC exhibits the optimum performance (i.e., an electrical conductivity of 57.1 S·cm^-1 at 700 ℃ in 5% (in volume fraction) H₂O atmosphere, and an area-specific resistance (ASR) of 0.19 Ω·cm² at 650 ℃ in an NSC|BZCYYb (BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ)|NSC symmetric cell, with only a ~2% increase in ASR after 100 h at 600 ℃). In a full-cell test with NSC|BZCYYb|Ni-BZCYYb, the oxygen electrode achieves power densities of 1273 mW·cm^-2 and 362 mW·cm^-2 at 650 ℃ and 500 ℃, respectively, and demonstrates a stable operation for 165 h at a constant current density of 0.54 A·cm^-2 at 600 ℃. This work demonstrates that the misfit-layered Na_0.15Sr_2.85Co₄O_9-δ material has a significant promising application in H-SOFCs.

In this study, three materials of the misfit-layered Na_0.15X_2.85Co₄O_9-δ (NXC, X=Ca, Sr, Ba; abbreviated as NCC, NSC, NBC) system were synthesized by a glycine-nitrate combustion method. These materials featured an alternating stacking structure composed of [X₂CoO_3-δ] and [CoO_2-δ] layers. The NXC series electrode materials were obtained via calcination in a muffle furnace at 800 ℃ for 2 h, followed by grinding. The intrinsic properties of the materials (i.e., electrical conductivity and thermal expansion coefficient) were characterized. Electrode slurries were prepared via grinding the materials, which were then screen-printed onto BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ (BZCYYb) electrolyte pellets to fabricate NXC|BZCYYb|NXC symmetric cells. These symmetric cells underwent temperature sensitivity, humidity sensitivity, and stability tests. The material with the optimal comprehensive performance was selected to construct NXC|BZCYYb|Ni-BZCYYb full cells. The full cells were characterized by current density-voltage measurement, electrochemical impedance spectroscopy (EIS) at 650-500 ℃, and relaxation time (DRT) analysis.

Among the three materials, NCC and NSC both exhibit well-formed phases, whereas NBC produces a significant amount of the secondary phase BaCoO_3-δ. The thermal expansion coefficients (TECs) of NCC and NSC are relatively low, while that of NBC is notably higher due to the high TEC of the secondary phase. In terms of electrical conductivity, NSC demonstrates the optimum performance among the three materials, achieving 40.8 S·cm^-1 at 500 ℃ in dry air, which is significantly superior to those of NCC and NBC. At 650 ℃, the polarization resistances (R_p) of NCC and NSC both are 0.190 Ω·cm², while NBC exhibits a higher R_p of 0.252 Ω·cm², indicating that Ca- and Sr-doped electrodes possess comparable charge transfer capabilities at elevated temperatures, whereas the Ba-doped material performs slightly worse. Also, NSC displays a superior performance in both humidity sensitivity and stability tests. Based on the analysis above, NSC in the NXC series with the maximum conductivity, catalytic activity, and stability is selected as an oxygen electrode for the NSC|BZCYYb|Ni-BZCYYb full cell for subsequent testing. NSC exhibits excellent performance and stability, delivering power densities of 1273, 1095, 704, 362, 170 mW·cm^-2 and 91 mW·cm^-2 at 650-400 ℃. Moreover, it demonstrates a stable operation for 165 h at an applied current density of 0.54 A·cm^-2, confirming its potential as an oxygen electrode for H-SOFCs.

This study synthesized a series of misfit-layered Na_0.15X_2.85Co₄O_9-δ (NXC, X=Ca, Sr, Ba; abbreviated as NCC, NSC, and NBC) oxygen electrode materials by a glycine-nitrate combustion method. The influences of elements Ca, Sr, and Ba on the crystal structure and electrochemical properties were systematically investigated. Among the synthesized materials, Na_0.15Sr_2.85Co₄O_9-δ (NSC) demonstrated optimal electrochemical performance and stability. It exhibited an electrical conductivity of 57.1 S·cm^-1 at 700 ℃ in a 5% H₂O+95% air atmosphere. The NSC symmetric cell showed the lowest area-specific polarization resistances (ASR) of 0.190, 0.323, 0.590 Ω·cm², and 0.911 Ω·cm² at 650-500 ℃, along with excellent long-term stability. These superior characteristics were further confirmed in NSC|BZCYYb|Ni-BZCYYb full-cell tests, achieving high power densities of 1273, 1095, 704, 362 mW·cm^-2 at 650-500 ℃, respectively. Moreover, the cell maintained stable operation for 165 h at an applied current density of 0.54 A·cm^-2, demonstrating a remarkable stability. These results indicated that the triple-conducting (H⁺/O^2-/e^-) misfit-layered NSC material could be a highly promising oxygen electrode candidate for intermediate-to-low temperature solid oxide cells.

Hierarchical porous nitrogen-doped carbon-supported Mo₂C particle composite materials (Mo₂C@PCN-X) were constructed by an anti-solvent method and a subsequent in-situ pyrolysis process with ammonium molybdate tetrahydrate and ammonium citrate as precursors, and sodium chloride as a template. The nitrogen-doped carbon pore structure and Mo₂C loading in Mo₂C@PCN-X were regulated via adjusting the addition ratio of ammonium molybdate tetrahydrate. The results show that the number of hollow cavities in Mo₂C@PCN-X increases with the increase in the amount of ammonium molybdate tetrahydrate added, providing abundant storage space for lithium polysulfides (Li₂S_n, n=4-8) and restricting the diffusion of LiPS through physical interactions. Furthermore, the Mo₂C particles exhibit significant adsorption capacity and catalytic activity toward LiPS, accelerating the conversion of soluble Li₂S_n to solid-state Li₂S₂/Li₂S, thereby effectively suppressing the shuttle effect. The S@Mo₂C@PCN-1.5 cathode delivers a high reversible discharge capacity of 1207 mA·h·g^-1 at 0.1 C and maintains 517 mA·h·g^-1 at 1.0 C. After 200 cycles, this cathode demonstrates a low per-cycle decay rate of merely 0.1%, exhibiting superior cycling stability compared to pristine S@PCN.

15 g of sodium chloride was dissolved in 50 mL of deionized water. Afterwards, 1.5 g of ammonium molybdate tetrahydrate [(NH₄)₆Mo₇O₂₄·4H₂O] and 4.786 g of ammonium citrate (C₆H₁₇O₇N₃) were sequentially added to the solution, followed by continuous stirring until complete dissolution. The mixed solution above was rapidly poured into 400 mL of industrial ethanol and vigorously stirred for 5 min. After precipitation, the NaCl@C₆H₁₇O₇N₃-1.5 precursor was obtained by filtration and drying. Also, NaCl@C₆H₁₇O₇N₃-0, NaCl@C₆H₁₇O₇N₃-1.0, and NaCl@C₆H₁₇O₇N₃-2.0 precursors were prepared via varying the addition amount of ammonium molybdate tetrahydrate (0, 1 g, and 2 g), respectively, based on the above procedure. The NaCl@C₆H₁₇O₇N₃-X (X=0, 1.0, 1.5, and 2.0) precursors were heated in a tube furnace to 450 ℃ at a rate of 5 ℃·min^-1 under an Ar-H₂ (10%, in volume fraction) mixed atmosphere for 2 h, and then continuously heated to 800 ℃ at the same rate and held for another 2 h. After cooling to room temperature, NaCl-Mo₂C@PCN-X powders were obtained. The powders were washed for three times with deionized water to remove the NaCl template (with template recovery), and dried at 70 ℃ to obtain Mo₂C@PCN-X composites and PCN support materials. Mo₂C@PCN-X was mixed with sulfur powder at a mass ratio of 3∶7, ground uniformly with a small amount of ethanol and dried. The mixture was heated in a tube furnace to 155 ℃ at a rate of 5 ℃·min^-1, held for 12 h, and then further heated to 200 ℃ and held for 20 min to remove the excess sulfur on the surface of Mo₂C@PCN-X. After natural cooling, the S@Mo₂C@PCN-X composite cathode material was prepared. In addition, S@PCN composite cathode material was also prepared as a control sample using PCN as a substrate according to the procedure above.

The analysis of micro-morphologies of PCN and Mo₂C@PCN-X composites shows that the number of elongated pore structures increases from Mo₂C@PCN-1.0 to Mo₂C@PCN-1.5, but decreases significantly from Mo₂C@PCN-1.5 to Mo₂C@PCN-2.0 as the addition amount of (NH₄)₆Mo₇O₂₄·4H₂O increases, possibly due to the collapse of excessive pore structures. Abundant pore structures are beneficial for the storage and transport of electrolytes. Compared with other samples, Mo₂C@PCN-1.5 exhibits a larger specific surface area and pore structure, which can provide more internal voids for sulfur loading and inhibit the dissolution of Li₂S_n. Meanwhile, the smaller pore diameters can enhance the adsorption capacity of carbon materials for polysulfides. Compared with pure carbon materials, the specific surface area of composites with added ammonium molybdate tetrahydrate increases significantly. This is likely because during the precursor preparation process, ammonium molybdate tetrahydrate crystallizes on the sodium chloride template after adding ethanol. In the subsequent carbonization process, ammonium molybdate tetrahydrate crystals extract carbon from the carbon material to form molybdenum carbide. In this process, the vacancies of extracted carbon form micropores, and unreacted molybdate leaves some micropores after washing. These micropores provide a larger specific surface area for the carbon material. However, the specific surface area decreases with the increase in the addition amount of ammonium molybdate tetrahydrate, possibly because the excessive addition causes larger crystal grains to form on the sodium chloride template. The larger grains extract too much carbon during the reaction, leading to the collapse of generated micropores. The adsorption capacity of the support materials for polysulfides is intuitively determined by visual experiments and UV-VIS absorption spectroscopy. After adsorption by Mo₂C@PCN-1.5, the solution color significantly fades, and the absorption peak intensities of Li₂S₆ and Li₂S₄ decrease significantly, indicating that the Mo₂C@PCN-1.5 support material can strongly adsorb polysulfides. The results of symmetrical battery and deposition experiments demonstrate that Mo₂C@PCN-1.5 with appropriate molybdenum carbide catalysis exhibits better polysulfide conversion kinetics. The electrochemical performance analysis of full batteries confirms that Mo₂C@PCN-1.5 has superior cycling and rate performance, as well as high sulfur loading capacity. As a cathode substrate, Mo₂C@PCN-1.5 is more conducive to promoting the retention of polysulfides and the utilization of active materials.

In this work, a Mo₂C@PCN-X composite material with a hierarchical pore structure was constructed by a green and facile anti-solvent strategy. The results showed that the introduction of the precursor (NH₄)₆Mo₇O₂₄·4H₂O had a regulatory effect on the crystallization behavior of the NaCl template, inducing the carbon component in the Mo₂C@PCN-X composite to form a hierarchical pore structure with additional cavities, and the cavity density was positively correlated to the molybdenum source concentration. When Mo₂C@PCN-X was used as a host for LSB batteries, the three-dimensional interconnected pores of the PCN matrix could promote electrolyte infiltration and adsorb soluble Li₂S_n (n=4-8) through physical action. Moreover, the Mo₂C particles loaded on its surface could enhance the chemical adsorption of Li₂S_n by the Mo₂C@PCN-X host material through d-p orbital hybridization, while reducing the energy barrier for Li₂S deposition/decomposition. However, Mo₂C could agglomerate as the loading amount increased, reducing the specific surface area of the material. Therefore, under the same conditions, the S@Mo₂C@PCN-1.5 positive electrode exhibited the optimum reversible discharge capacity and capacity retention rate during cycling. The crystallization regulation mechanism could provide an idea for the controllable preparation of porous carbon-based composites. Future research could focus on reducing the particle size of Mo₂C through strategies such as surface functional modification, so as to provide a theoretical reference for the design of positive electrode materials for high-energy-density LSBs.

The poor interface characteristics between inorganic perovskite and the electron transport layer limit the improvement of the photovoltaic performance of inorganic perovskite solar cells (IPSCs). In this paper, the buried interface was treated with ethylenediaminetetraacetic acid (EDTA), and four carboxyl groups of EDTA reacted with the hydroxyl groups of SnO₂ to improve the interface characteristics, enhance the crystallization quality of the inorganic perovskite film, reduce the defect state density and suppress non-radiative recombination. Finally, the n-i-p type device with the composition of CsPbI_2.25Br_0.75 prepared in air achieved a power conversion efficiency (PCE) of 18.84% and excellent stability.

The In-doped Tin Oxide (ITO) glass substrate was ultrasonically cleaned in glass cleaner, deionized water and isopropyl alcohol solution for 20 min, respectively. Before the use, the FTO substrate was treated with ultraviolet ozone for 20 min. Then, 12% SnO₂ nanosolution was diluted for three times with water and spin-coated on the surface of ozone-treated ITO glass at 3000 r/min for 30 s, followed by annealing in air at 150 ℃ for 30 min. After cooling to room temperature, 0.1 mg/mL EDTA (H₂O) was spin-coated on the surface of SnO₂ and annealed at 100 ℃ for 10 min. The preparation of perovskite precursor solution and thin film was consistent with the that from previously reported literature^[30], except that the preparation environment of the perovskite film was changed in air with a humidity of < 25%. 40 μL of Spiro-OMeTAD was spin-coated on the surface of perovskite film at 3000 r/min for 30 s as a hole transport layer. Finally, 80 nm of Au was evaporated on the surface of the hole transport layer by evaporation equipment as a metal electrode.

The pinholes on the surface of the perovskite in the Target group are significantly reduced, corresponding to a lower defect state density and a superior photovoltaic performance. The PL intensity of the Target group films is significantly greater than that of the Control group, indicating that non-radiative recombination is suppressed after EDTA treatment. After EDTA treatment, the average carrier lifetime increases from 75.10 ns to 113.31 ns. The optimum PCE is increased from 16.68% of the control device to 18.84%. The current density is verified by the external quantum efficiency test of the solar cell. The integral current density increases from 18.42 mA/cm² to 18.78 mA/cm² due to the improvement of the interface contact characteristics between SnO₂ and perovskite by EDTA. The steady-state output power curve of the best PCE device of the target device is negligible within 280 s. Two types of devices are placed in an environment at 25 ℃ and a humidity of 20%-30%. After 250 h, the control device retains 73.39% of its initial PCE, while the Target device maintains 81.41%. The improvement in stability is attributed to the EDTA enhancement of the interface contact between SnO₂ and the inorganic perovskite, suppressing non-radiative recombination at the interface and reducing the defect state density.

The EDTA was used to modify the buried interface. The four carboxyl groups of EDTA reacted with the hydroxyl groups of the SnO₂ layer, improving the interface contact characteristics between SnO₂ and perovskite and facilitating the efficient extraction of electrons. Non-radiative recombination at the interface was suppressed and the defect state density was reduced. Ultimately, a n-i-p type device with a composition of CsPbI_2.25Br_0.75 prepared in air achieved a PCE of 18.84%. This could provide a scientific approach for advancing the practical application of IPSCs.

Commercial ternary cathode materials have their theoretical performance limits. Consequently, enhancing energy density, reducing costs, and improving cycling stability without compromising safety are critical challenges for both academia and industry. Among the existing candidates, LiNi_0.9Mn_0.1O₂(NM91) offers a significant potential due to its high specific capacity, cost-effectiveness, and low-cobalt (or cobalt-free) nature. However, ahigh nickel content induces severe structural instability. Elevated Ni levels exacerbate Li⁺/Ni²⁺ cation disordering, thus disrupting the α-NaFeO₂-type layered structure and impeding lithium-ion de/intercalation kinetics, which degrades a rate capability. Furthermore, during high-voltage cycling (>4.3 V), detrimental interfacial reactions occur, i.e., electrolyte decomposition, transition metal dissolution, and the formation of Ni-rich rock-salt or amorphous phases. These degradation mechanisms destabilize the electrode-electrolyte interface, accelerate capacity fade, exacerbate electrode polarization, and severely compromise cycling longevity and battery safety. To address these challenges, this study was to propose an innovative Mg/Nb/Ti co-modification strategy to enhance the structural stability and electrochemical performance of single-crystal LiNi_0.9Mn_0.1O₂ cathodes.

The Ni_0.9Mn_0.1(OH)₂ precursor was first homogeneously blended with LiOH·H₂O and flux under strictly controlled stoichiometric conditions (i.e., at a Li : (Ni+Mn) molar ratio of 1.05∶1.00 and a (LiCl+KCl) ∶ (Ni+Mn) mass ratio of 0.3 ∶ 1.0). The mixture was then calcined in a flowing oxygen atmosphere, heated to 550 ℃ at 3 ℃/min (300 min hold), ramped to 900 ℃ at the same rate for 60 min, cooled controllably at 5 ℃/min to 820 ℃ for 840 min, and finally cooled to ambient temperature, yielding a phase-pure single-crystal LiNi_0.9Mn_0.1O₂ (designated SC-NM91).

For the doped samples, Ni_0.9Mn_0.1(OH)₂ precursor was homogenized with LiOH·H₂O, Mg(NO₃)₂, and C₁₀H₅NbO₂₀·xH₂O in anhydrous ethanol under vigorous agitation. C₁₆H₃₆O₄Ti was added in dropwise, followed by continuous stirring and drying at 60 ℃ until complete solvent evaporation. The resultant mixture had a controlled stoichiometry of Li ∶ (Ni+Mn) ∶ Mg ∶ Nb ∶ Ti = 1.05 : (1-x-y-z) ∶ x ∶ y ∶ z (x=0.005, 0.010, 0.020; y=0.002 5, 0.005 0, 0.010 0; z=0.01).

The identical solid-state sintering protocol used for SC-NM91 was applied to synthesize Mg/Nb/Ti tri-doped LiNi_0.9-x-y-zMn_0.1Mg_xNb_yTi_zO₂ cathodes with controlled dopant gradients. The compositions of SC-NM91-0.5Mg@0.25Nb@1Ti, SC-NM91-1Mg@0.5Nb@1Ti, and SC-NM91-2Mg@1Nb@1Ti were produced via unified thermal processing.

Among the modified cathodes, SC-NM91-0.5Mg@0.25Nb@1Ti demonstrates significantly enhanced cycling stability and superior overall electrochemical performance, compared to SC-NM91-1Mg@0.5Nb@1Ti and SC-NM91-2Mg@1Nb@1Ti.

The XRD patterns reveal a systematic peak shift toward lower angles in the modified samples relative to SC-NM91, indicating a lattice expansion along the c-axis induced by elemental doping. SC-NM91-0.5Mg@0.25Nb@1Ti exhibits enhanced cationic ordering with an R-factor of 1.749 0 versus 1.641 8 for pristine SC-NM91, demonstrating that optimized Mg/Nb/Ti co-doping effectively mitigates cationic disordering and stabilizes the layered structure. The SEM images indicate that SC-NM91 comprises irregular particles (the diameter of ~1 µm) with a non-uniform distribution and a broad size range, including oversized particulates. Increasing Mg/Nb/Ti doping concentration yields a significant morphological evolution. The particle distribution becomes more homogeneous, particle size gradually decreases, and the EDS mapping confirms spatially uniform elemental dispersion, verifying an effective dopant incorporation. The XPS analysis reveals that Mg/Nb/Ti doping effectively modulates the material surface electronic structure and valence state distribution, enhances structural stability, increases the Ni³⁺ proportion, consequently improving the electrochemical performance.

SC-NM91-0.5Mg@0.25Nb@1Ti has a superior rate capability across multiple current densities, significantly outperforming other specimens. This indicates that optimal doping enhances a structural stability, while maintaining high lithium-ion transport kinetics. When cycled at 1 C under different cut-off voltages (i.e., 4.3 V and 4.4 V), SC-NM91-0.5Mg@0.25Nb@1Ti electrode exhibits the maximum capacity retention rate, showing a remarkable improvement over counterparts. These results verify that multi-element doping combined with surface modification effectively enhances electrochemical properties. Furthermore, its differential capacity curves exhibit more symmetric phase transition peaks, significantly reduced voltage hysteresis, and compact/stable peak profiles, indicating enhanced phase transition reversibility and substantially improved structural stability. The electrochemical impedance spectroscopy (EIS) primarily reveal two key parameters, i.e., series resistance (R_s) and charge transfer resistance (R_ct), reflecting intrinsic material resistance and the electron transfer barrier at the electrode-electrolyte interface, respectively. After 100 cycles, SC-NM91-0.5Mg@0.25Nb@1Ti exhibits significantly lower resistance values rather than pristine SC-NM91. This demonstrates that Mg/Nb/Ti co-modification effectively mitigates electrolyte corrosion, stabilizes the interfacial structure, and facilitates the formation of arobust cathode electrolyte interphase film. Consequently, the modified electrode maintains efficient charge transfer kinetics during prolonged cycling, while retarding R_ct degradation. Finally, the cyclic voltammetry (CV) analysis reveals that the modified sample has a distinct hysteretic shift in the oxidation peak and reduces peak intensities, compared to the unmodified sample. Nevertheless, the high degree of peak overlap across cycles indicates that the synergistic doping-coating modification significantly suppresses electrochemical polarization and enhances interfacial reaction kinetics, thereby contributing to superior electrochemical performance.

This study systematically explored a synergistic co-modification strategy combining Mg/Nb bulk doping and Ti surface coating for SC-NM91 high-nickel cathodes. The optimally designed SC-NM91-0.5Mg@0.25Nb@1Ti sample that was fabricated via high-temperature solid-state synthesis could exhibit the superior structural stability and electrochemical performance. It demonstrated a capacity retention of 89.2% at 4.3 V after 100 cycles, significantly exceeding the unmodified counterpart (i.e., 73.3%), while maintaining a retention of 66.5% at 4.4 V, indicating the exceptional high-voltage stability. The mechanistic investigations revealed that Mg doping primarily suppressed Li/Ni cation mixing and inhibited the H1→M phase transition at low voltages, while Nb doping stabilized oxygen frameworks, mitigated oxygen release under high-voltage conditions, and enhanced H2→H3 phase transition reversibility. Ti⁴⁺doping reinforced transition metal layer stability and suppressed Ni⁴⁺-induced lattice oxygen release at high voltages, extending cycle life. The concomitant formation of TiO₂/LiTi₂O₄ coating layers during thermal processing effectively blocked parasitic reactions and boosted electronic conductivity, collectively improving interfacial integrity and rate capability. The electrochemical characterization confirmed reduced R_ct post-cycling and diminished redox peak potential separation in CV, evidencing enhanced reaction kinetics and suppressed polarization. This co-modification approach could elevate the comprehensive performance of SC-NM91 cathodes, establishing an effective paradigm for developing high-energy-density lithium-ion battery cathodes with a robust stability.

Achieving the "carbon peaking and carbon neutrality" targets requires efficient energy storage technologies. Supercapacitors with the high power density, rapid charge-discharge, and long cycle life show a great potential in renewable energy, electric vehicles, and smart grids. However, their low energy density limits wider applications. Transition metal oxides such as RuO₂ and MnO₂ are promising electrode materials due to their reversible faradaic reactions and high theoretical capacitance. Single-component oxides suffer from insufficient active sites and structural degradation, impairing rate capability and stability. Multi-metal oxide strategies leverage synergistic effects to optimize lattice, charge distribution, morphology, and performance. Cobalt-based oxides provide abundant Co²⁺/Co³⁺ redox pairs, manganese adds multiple valence states and structural buffering, while zinc enhances conductivity and stability. Nevertheless, low conductivity and poor kinetics persist. Oxygen vacancies improve conductivity, tune band structure, and create active sites via reducing bandgap and accelerating kinetics. In this work, oxygen-vacancy-rich Ov-Co₃Zn₁Mn_0.5O₅ nanoflowers were synthesized via hydrothermal-annealing-NaBH₄ reduction and multi-metal synergy and defect engineering to optimize morphology and electronic structure. This approach could validate the synergistic benefits and offer a strategy for high-performance transition metal oxide supercapacitor electrodes.

All chemicals were of analytical grade and used as received. Nickel foam substrates (2 cm × 3 cm) were pretreated in HCl solution of 3 mol/L under ultrasonication for 5 min to remove surface oxides and thoroughly rinsed with deionized water. For the synthesis of Co₃Zn₁Mn_0.5O₅, stoichiometric amounts of Co(CH₃COO)₂·6H₂O (3 mmol), Zn(CH₃COO)₂·H₂O (1 mmol), MnC₄H₆O₄·4H₂O (0.5 mmol), and urea (0.2 g) were dissolved in deionized water of 60 mL to form a homogeneous precursor solution. The solution together with the pretreated nickel foam was sealed in a 100 mL Teflon-lined autoclave and maintained at 120 ℃ for 6 h. After natural cooling, the nickel foam-supported precursor was washed, dried, and subsequently annealed in air at 400 ℃ for 2 h, yielding Co₃Zn₁Mn_0.5O₅ with a mass loading of 1.12 mg·cm^-2. For comparison, binary and other ternary oxides (i.e., Co₃Zn₁O₄, Co₃Mn_0.5O₄, Zn₁Mn_0.5O₂, Co₂Zn₁Mn_0.5O₄, and Co₄Zn₁Mn_0.5O₆) were prepared under the same conditions above. Oxygen vacancies were introduced via immersing the annealed Co₃Zn₁Mn_0.5O₅ in NaBH₄ solution for 12 min, followed by vacuum drying at 80 ℃ for 2 h to obtain Ov-Co₃Zn₁Mn_0.5O₅ (a mass loading of 1.02 mg·cm^-2). Comparative samples Ov-Co₂Zn₁Mn_0.5O₄ and Ov-Co₄Zn₁Mn_0.5O₆ were also prepared.

The morphology was determined by field-emission scanning electron microscopy (S-4800, Hitachi Co., Japan) and transmission electron microscopy (JEM-2100F, JEOL Co., Japan). The rystal structure was identified by X-ray diffraction (D/MAX-2500, Rigaku Co., Japan, Cu K_α, λ = 0.154156 nm). The surface chemical states and valence distributions were analyzed by X-ray photoelectron spectroscopy (K-Alpha, Thermo Co., USA). The oxygen vacancy concentration was quantified by electron paramagnetic resonance (EMXplus, Bruker Co., Germany) and thermogravimetric analysis (TG 209 F3 Netzsch Co., Germany). The electrochemical measurements were conducted in a three-electrode configuration with 6 mol/L KOH electrolyte using a CHI760e workstation. The cyclic voltammetry and galvanostatic charge-discharge within 0-0.5 V at different scan rates of 10-100 mV·s^-1 and various current densities were detremined. The electrochemical impedance spectroscopy was performed on a BioLogic SP-150 workstation. The density functional theory calculations were carried out by a software named Materials Studio package using the projector-augmented wave method.

The three-step hydrothermal-annealing-NaBH₄ reduction process yields uniform flower-like Ov-Co₃Zn₁Mn_0.5O₅ nanoflowers directly grown on nickel foam. The SEM images reveal that the binary oxides display irregular nanosheets or nanowires, whereas the ternary Co₃Zn₁Mn_0.5O₅ forms large-sized nanosheets assembled into a loose porous flower-like morphology that provides abundant redox active sites. After NaBH₄ treatment, the overall morphology is preserved, while porosity is markedly increased. The TEM images confirm the porous nanosheet structure in the both samples, with Co₃Zn₁Mn_0.5O₅ exhibiting more mesopores and atomic-level defects evidenced by disordered lattice fringes. The HRTEM images display lattice spacings of 0.202 nm and 0.156 nm, corresponding to the plane (400) of MnCo₂O_4.5 and the plane (511) of ZnCo₂O₄. The EDS mapping shows a homogeneous distribution of elements Co, Zn, Mn and O, and Mn content is lower than the nominal ratio. The XRD patterns confirm the coexistence of cubic spinel MnCo₂O_4.5 and ZnCo₂O₄ phases in all the samples, and Ov-Co₃Zn₁Mn_0.5O₅ shows a higher crystallinity. The TGA and EPR unambiguously verify abundant oxygen vacancies. The XPS analysis reveals positive shifts in Co 2p, Mn 2p, Zn 2p, and O 1s binding energies after reduction, accompanied by increased proportions of low-valence Co²⁺, Mn³⁺, and a larger O_V peak area, confirming mixed-valence states and defect formation. The results of electrochemical tests demonstrate clear synergistic effects. The CV curves at 10 mV·s^-1 exhibit the largest integrated area for the ternary composition. The oxygen-vacancy introduction further enlarges the area due to more active sites and lowered OH^- intercalation barrier. The b-values of 0.70 and 0.77 indicate combined diffusion and pseudocapacitive contributions. The GCD measurements deliver an ultrahigh specific capacitance of 1509.8 F·g^-1 at 2 A·g^-1 and retain 809.1 F·g^-1 at 20 A·g^-1, demonstrating an excellent rate capability. The assembled Ov-Co₃Zn₁Mn_0.5O₅//AC asymmetric supercapacitor maintains stable CV shapes up to 100 mV·s^-1 within a 1.6 V window, achieves a high energy density of 53.8 W·h·kg^-1 at 750 W·kg^-1, and retains 76.4% capacitance after 5000 cycles with the Coulombic efficiency of 99%. The DFT calculations reveal that oxygen vacancies eliminate the original 0.098 eV bandgap, introduce mid-gap defect states, increase carrier concentration and facilitate electron hopping between low-valence Co²⁺and Mn³⁺ sites, thereby significantly enhancing conductivity and redox kinetics.

The flower-like Ov-Co₃Zn₁Mn_0.5O₅ with rich oxygen vacancies was successfully synthesized by a facile hydrothermal-annealing-NaBH₄ reduction method. The unique nanosheets-assembled nanoflower structure could expose abundant active sites and enhance redox kinetics. The introduction of oxygen vacancies regulated the electronic structure, improved conductivity, and induced low-valence Co²⁺ and intermediate Mn³⁺ to promote redox reactions. The Ov-Co₃Zn₁Mn_0.5O₅ electrode delivered a high specific capacitance of 1509.8 F·g^-1 at 2 A·g^-1 with the excellent rate performance. The assembled asymmetric supercapacitor achieved 53.8 W·h·kg^-1 energy density at 750 W·kg^-1 and retained 76.4% of its initial capacitance after 5000 cycles with the Coulombic efficiency of 99%. This work could demonstrate the synergistic optimization of multi-metal composition and oxygen vacancy engineering for advanced transition metal oxide electrodes in supercapacitors.

Sodium-ion batteries (SIBs) have attracted much attention as a promising alternative to lithium-ion batteries due to the abundance and low cost of sodium resources. Among various cathode materials, layered oxide NaNi_1/3Fe_1/3Mn_1/3O₂ (NFM) offers some advantages such as environmental friendliness, low toxicity, and high theoretical capacity. However, its practical application is severely hindered by structural instability, poor cycling stability, and inferior rate capability, which originate mainly from undesirable

electrode-electrolyte interfacial side reactions, irreversible phase transitions during Na⁺ insertion/extraction, and sluggish Na⁺diffusion kinetics. Surface coating is considered as an effective strategy to address these issues. In particular, Al₂O₃ coatings can suppress parasitic reactions and stabilize the layered structure. Nevertheless, conventional coating methods often involve complex, multi-step processes such as atomic layer deposition (ALD) or post-annealing, which are costly and less scalable. In this work, we developed a facile one-step wet-chemical route combined with solid-state calcination to obtain an Al₂O₃ coating on NFM. The aim was to simultaneously enhance the cycling stability and rate capability via forming a protective layer, while enabling partial Al³⁺doping into the near-surface lattice. In addition, the underlying mechanism was also investigated.

The pristine NFM material was synthesized via mixing Ni_1/3Fe_1/3Mn_1/3(OH)₂ precursor with Na₂CO₃ (molar ratio 1.000∶0.525), followed by pre-sintering at 500 ℃ for 5 h, and then calcined in O₂ atmosphere at 850 ℃ for 15 h. For Al₂O₃ coating, different molar fractions (0.5%, 1.0%, and 2.0%) of Al(NO₃)₃·9H₂O were dissolved in ethanol, and the precursor was added. The mixture was stirred, ultrasonicated, and then dried at 70 ℃ and then at 120 ℃. The obtained Al-precoated precursor was calcined under the same conditions as the pristine NFM, obtaining the samples denoted as NFM-0.5A, NFM-1A, and NFM-2A, respectively.

CR2032 coin-type half-cells were assembled in an argon-filled glove box (Mikrouna Super 1220/750/900, China) using sodium metal as a counter electrode, glass fiber as a separator, and 1.0 mol/L NaClO₄ in ethylene carbonate (EC)/propylene carbonate (PC) (1∶1 by volume) with 5% (in mass fraction) fluoroethylene carbonate (FEC) as an electrolyte. The working electrode consisted of 80% (in mass fraction) active material, 10% (in mass fraction) carbon black, and 10% (in mass fraction) polyvinylidene fluoride (PVDF) in N-methyl-2-pyrrolidone (NMP, ca. 1.0-1.5 mL).

The crystal structure was characterized by X-ray diffraction (XRD) with Rietveld refinement. The surface morphology and element distribution were determined by scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). The surface chemical states were analyzed by X-ray photoelectron spectroscopy (XPS). The electrochemical performance (i.e., the cycling stability at various rates (i.e., 1, 2, and 5 C) and the rate capability from 0.1 C to 10.0 C) were evaluated by a battery test system. The electrochemical impedance spectroscopy (EIS) was performed at 0.01-100.00 kHz with an amplitude of 5 mV. The Na⁺ diffusion coefficient was determined by galvanostatic intermittent titration technique (GITT).

The XRD patterns of pristine NFM and NFM-1A show no impurity peaks, both exhibiting an O3-type α-NaFeO₂ layered structure with a space group . The peaks (003) and (104) of NFM-1A shift slightly, and the Rietveld refinement reveals increased lattice parameters a, c, and cell volume (from 2.980 Å, 15.960 Å, and 122.755 ų for NFM to 2.983 Å, 15.988 Å, and 123.160 ų for NFM-1A), indicating partial Al³⁺ doping into the near-surface lattice, which expands the interlayer spacing and facilitates Na⁺ transport.

The SEM images show that NFM-1A and NFM-2A have a uniform coating layer. The TEM images and EDS spectra indicate a distinct Al₂O₃ coating layer with a thickness of approximately 15 nm on the NFM surface, and a small amount of Al³⁺ diffuses into the shallow lattice, forming strong Al-O bonds. The XPS analysis further shows the presence of Al₂O₃ on the surface, as evidenced by the Al 2p peak at 73.08 eV. The binding energies of Ni 2p, Fe 2p, and Mn 2p in NFM-1A shift slightly to lower values, compared with pristine NFM, which is attributed to a charge compensation from Al³⁺ incorporation, thus stabilizing the structure.

The results of electrochemical tests demonstrate that the NFM-1A electrode exhibits the optimum overall performance. The initial discharge capacities at 0.1 C are 140.53, 143.34, 145.99 mA·h·g^-1, and 140.48 mA·h·g^-1 for NFM, NFM-0.5A, NFM-1A, and NFM-2A, respectively, with the corresponding Coulombic efficiencies of 88.67%, 86.06%, 90.78%, and 87.62%. After 150 cycles at 1 C, the discharge capacities are 91.83, 104.46, 113.38 mA·h·g^-1, and 99.80 mA·h·g^-1, with the capacity retentions of 68.62%, 77.14%, 80.77%, and 77.16%, respectively. At a higher rate of 2 C, NFM-1A retains 82.77% of its initial capacity after 150 cycles (112.42 mA·h·g^-1), and at 5 C, it retains 73.31% after 300 cycles (92.20 mA·h·g^-1). The results of rate capability test show that NFM-1A delivers a discharge capacity of 98.0 mA·h·g^-1 at 10 C, far exceeding that of pristine NFM (56.26 mA·h·g^-1). When the rate is 0.1 C, NFM-1A recovers 92.1% of its initial capacity (137.16 mA·h·g^-1), demonstrating the excellent structural reversibility.

The GITT measurements reveal that the average Na⁺ diffusion coefficient of NFM-1A (1.20×10^-10 cm²/s) is approximately twice greater than that of pristine NFM (5.89×10^-11 cm²/s), confirming that the Al₂O₃ coating with partial Al³⁺ doping broadens the Na⁺transport channels. The EIS analysis shows that after 150 cycles, the charge transfer resistance (R_ct) of NFM-1A (347.40 Ω) is significantly lower than that of pristine NFM (544.48 Ω), and the conductive interface resistance (R_f) is also reduced (262.80 Ω vs. 344.39 Ω). The post-cycling XRD patterns and SEM images indicate that NFM-1A maintains better crystallinity and intact spherical particle morphology without cracks, whereas pristine NFM exhibits severe particle fragmentation. These results confirm that the Al₂O₃ coating effectively suppresses interfacial side reactions, stabilizes the layered structure, and preserves the integrity of secondary particles during prolonged cycling.

An Al₂O₃-coated NFM cathode material was prepared by a one-step wet-chemical method and subsequent solid-state calcination. The optimal coating amount was 1% (in mole fraction) (NFM-1A). The Al₂O₃ coating acted as a physical barrier to suppress electrode-electrolyte interfacial side reactions and, simultaneously, partial Al³⁺ doping into the near-surface lattice formed strong Al-O bonds, expanded the interlayer spacing, and enhanced Na⁺ diffusion kinetics. Consequently, NFM-1A exhibited significantly improved cycling stability (i.e., retention after 150 cycles of 80.77% at 1 C, 82.77% at 2 C, and 73.31% at 5 C) and outstanding rate capability (i.e., 98.0 mA·h·g^-1 at 10 C with capacity recovery of 92.1%). This work could provide a simple and scalable strategy for developing high-performance layered oxide cathodes for sodium-ion batteries.

Lithium-ion batteries (LIBs) with a high energy density are critical for advancing electric vehicles and renewable energy storage systems. Silicon oxycarbide (SiOC) anode materials emerge as promising candidates due to their high cycling stability, suitable operating potential, low cost, and environmental compatibility. Unlike conventional silicon anodes that suffer from severe volume expansion (i.e., >300%), SiOC materials benefit from the uniform distribution of silicon and carbon in an atomic scale, forming protective Li₂O and lithium silicate layers during initial lithiation that mitigate volume changes. However, a practical implementation of SiOC anodes remains challenging due to their intrinsically low electronic/ionic conductivity and significant volumetric changes during cycling, leading to electrode pulverization, loss of electrical contact, and excessive solid-electrolyte interphase (SEI) growth. In this study, a novel synthesis strategy was proposed to create SiOC anodes with engineered yolk-shell and porous architectures that could simultaneously optimize structural stability, ionic/electronic transport, and interfacial properties.

This work employed a meticulously controlled sol-gel process followed by selective etching under mild alkaline conditions to fabricate SiOC anode materials with distinctive architectures. A yolk-shell structured material (YS@C) was prepared by a sequential addition approach via incorporating 1,4-bis(triethoxysilyl)benzene (BTEB) to form the core, and then adding tetraethoxysilane (TEOS) to create the shell. For the porous material (P@C), BTEB and TEOS were introduced simultaneously. The structures both underwent selective etching with a 2.4 mol/L Na₂CO₃ solution, removing portions of the inorganic silica, while preserving the organic-inorganic hybrid framework. Subsequently, resorcinol-formaldehyde resin was coated onto the etched structures and carbonized in 10% H₂/Ar atmosphere at 800 ℃ to form conductive carbon layers. The structural and chemical properties were determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and BET surface area analysis. The electrochemical performance was evaluated through cyclic voltammetry, galvanostatic charge-discharge testing, rate capability analysis, long-term cycling, and impedance spectroscopy, respectively.

The mild alkaline etching strategy produces monodisperse YS@C particles (with the sizes of 250-270 nm) featuring a distinctive yolk-shell structure with an intermediate void space, and P@C particles (with the sizes of 320-350 nm) with uniformly distribute internal pores. The structural analyses reveals amorphous characteristics with carbon contents of 75.51% for YS@C and 68.2% for P@C. The specific surface areas measured are 17.041 m²/g for YS@C and 27.458 m²/g for P@C, with the average pore sizes of 2.371 nm and 2.561 nm, respectively. The XPS analysis demonstrates different silicon valence states, with the average values of 2.796 9 for YS@C and 2.999 2 for P@C, indicating varying degrees of silicon oxidation that affect the electrochemical behavior.

In electrochemical testing, YS@C delivers the superior performance with an initial Coulombic efficiency of 55%, compared to 49% for P@C. Most significantly, YS@C maintains an exceptional cycling stability with specific capacities of 453 mA·h·g^-1 after 550 cycles at 0.5 A/g and 361 mA·h·g^-1 after 1000 cycles at 1 A/g, with the Coulombic efficiency consistently of > 99% after the sixth cycle. The kinetic analyses reveals the superior Li⁺ diffusion coefficient and remarkable pseudocapacitive contribution of YS@C (i.e., 82.2% at 2.0 mV/s) due to its shortened ion diffusion pathways. The post-cycling SEM examination confirms the structural integrity after 300 cycles of YS@C, while P@C exhibits significant cracking and degradation.

This research demonstrated that the gradient composition and hierarchical architecture of YS@C, featuring a high-capacity siloxane-rich core, intermediate void space, and protective carbon/SiOx shell, could collectively address the fundamental limitations of SiOC anode materials. The internal void space effectively accommodated volume expansion during lithiation/delithiation, while the carbon-rich shell enhanced conductivity and minimized detrimental side reactions with the electrolyte. The mild alkaline etching approach presented could offer a gentle yet effective method for engineering complex architectures without damaging the organic components critical for performance. The exceptional electrochemical performance of YS@C, particularly its unprecedented cycling stability at high current densities, could establishe a benchmark for SiOC-based anodes. This work could advance the development of high-performance lithium-ion battery anodes and provide valuable design principles for engineering gradient-structured materials for various energy storage applications. Future research could focus on scaling this synthesis approach and exploring its applicability to other conversion/alloying-type electrode materials requiring volume change accommodation.

Germanium-based anode materials have achieved significant progress in lithium-ion batteries, primarily in cost reduction, structural optimization, and interface engineering. High material costs restrict large-scale application, thus prompting the development of diverse Ge sources (e.g., GeO₂, organic precursors), Ge/metal and Ge/metalloid composites, and Ge-based high-entropy alloys. Ge combined with conductive metals like Cu or Ni improves electrical conductivity and structural stability, while pairing with active elements like Si or Sn mitigates volume expansion. In high-entropy systems, Ge can regulate lithiation behavior, effectively controlling volume change.

To address severe volume expansion during cycling that leads to material pulverization and capacity decay, various nanostructural materials including Ge nanoparticles, nanowires, and porous frameworks are designed. Nanoparticles have low expansion and fast kinetics, requiring artificial SEI layers and conductive matrices for stability. Ge nanowires exhibit radial resilience and axial flexibility, especially when directly grown on current collectors, offering a practical potential. Porous Ge integrates nanoscale activity with a high tap density, improving energy density, while avoiding particle agglomeration.

Interface instability and poor conductivity at a high current are also challenges for Ge-based anodes. The reactive surface of Ge can form unstable SEI layers, limiting performance. To address this, some engineered artificial SEI coatings such as N-doped carbon, heterojunction-carbon, and TiO₂ are developed to enhance ion/electron transport and mechanical integrity. In addition, a uniform dispersion of nanoscale Ge within conductive networks also improves fast-charging capabilities and cycling stability. Integrating structure and composition design through high-throughput element screening, one-step synthesis, and precise structural tuning is a key to reducing Ge dependency and enhancing performance. Further advancement requires in-situ characterization and multiscale simulations to uncover lithiation-induced phase transitions and stress evolution, facilitating the transition of Ge-based anodes from lab-scale research to industrial application.

The market adoption of germanium-based anodes is expected to follow a trajectory starting from high-end applications and gradually expanding to broader markets. In the short term, their use focuses on niche sectors with extreme requirements for energy density and fast charging but low sensitivity to cost, such as aerospace, military equipment, advanced medical devices, and long endurance drones. In the medium to long term, as manufacturing costs decrease and processing techniques become mature, germanium is expected to serve as a dopant or an alloying modifier for mainstream anode materials like silicon and tin, enhancing their kinetics and structural stability, and thereby indirectly improving the range and fast-charging performance of electric vehicle batteries. China has a unique strategic advantage in the global germanium supply chain. China develops a complete technological system covering refining, purification, and deep processing, enabling efficient production of high-purity precursors such as GeO₂ and GeCl₄. In parallel, the extensive recycling of germanium-containing by-products from industries like optical fibers, infrared optics, and solar cells creates a sustainable "resource-product-recycling" loop. These advantages significantly lower the marginal cost of use and ensure resource security, offering a practical and competitive environment to overcome cost barriers and scale up applications.

Diamond is a novel optoelectronic material with a tremendous application potential, injecting new vitality and opportunities into the development of optoelectronic technology. In laser technology, diamond exhibits excellent gain parameters, stability, and thermal properties, offering outstanding advantages in high-power laser applications. The existing applications in high-power Raman and Brillouin lasers yield remarkable results. Doped diamond serves as a probe material with superior performance parameters and high irradiation resistance, enabling stable high-precision detection and extending detector lifespans in harsh environments. In the UV and deep UV wavelength bands, diamond outperforms predecessor materials (e.g. silicon) in terms of stability and durability.

Diamond has attracted recent attention in the semiconductor field during the post-Moore era, demonstrating an exceptional application potential in electronic devices. Research on diamond Schottky barrier diode (SBD) and diamond p-n junction diode becomes popular, with a significant progress achieved in breakdown voltage, switching time, on-resistance, and other performance parameters.

Therefore, the following outlooks are described for the utilization of optoelectronic properties of diamond. 1) The material quality is crucial for its optoelectronic applications. However, the synthesis technology for high-quality, low-defect diamond remains immature. Future research must focus on reducing the synthesis costs of optical-grade and electronic-grade diamond with an enhanced growth rate. 2) Despite diamond possesses excellent thermal properties, thermal lensing effects still occur during high-power laser operation. The in-depth studies of heat sources and heat distribution within crystals are necessary to achieve higher power and conversion efficiency in diamond lasers. 3) Elemental doping is a critical challenge for diamond-based devices, especially difficult for n-type doping. Future research should conduct further mechanistic and experimental studies on n-type doping of diamond. 4) Most diamond electronic devices are still in the research stage, with considerable progress needed before large-scale, practical applications can be realized, urgently requiring more extensive theoretical and experimental efforts.

SOFC research shifts from single-cell materials to stack-level system integration. The experimental evidence shows that the contact between critical stack components is a dominant bottleneck governing both power output and lifetime. The anode side, operating in a reducing atmosphere and forming a metal-to-metal contact, exhibits a contact resistance, which is five orders of magnitude lower than the oxide-to-oxide interface on the cathode side and can be therefore neglected. The cathode side, in contrast, must rely on a current-collector/coating system that simultaneously ensures electron collection, stress buffering and oxidation protection. Consequently, future interface optimization will revolve around a three-dimensional, "current-collector material, interconnect coating and surface roughness" synergistic design framework.

Current-collector development evolves from noble metals to oxides and onward to graded, dual-phase composites. These systems aim to deliver conductivities on the order of kilosiemens/cm, while achieving triple matching-thermal, mechanical and chemical-with both the cathode and the interconnect through coordinated control of composition, microstructure and porosity.

Meanwhile, an accurate quantification of interfacial resistance remains a critical challenge. Conventional four-point measurements are limited by stack hermeticity, yielding only the total resistance, making it impossible to isolate the true interfacial contribution. The next step involves embedding ultrathin leads within the stack to couple AC impedance spectroscopy with in-situ voltage monitoring, thereby tracking the interfacial state of every repeating unit in real time. Post-mortem laser confocal microscopy and atomic force microscopy will be employed to establish quantitative correlations among surface roughness, contact depth and power degradation, creating a data-closed loop for predictive interface engineering.

The existing interface tuning still relies heavily on trial and error, and outcomes remain unpredictable. Understanding interfacial mechanisms can favor the design of SOFC stacks to lock in optimal clamping pressures, roughness windows and material combinations, thereby achieving a precise performance control. This mastery is essential to realizing commercial durability targets of tens of thousands of hours and laying the foundation for large-scale deployment in distributed generation.

The recycling and regeneration of spent LFP cathodes are essential for environmental protection and resource sustainability. Direct regeneration is the most economically and environmentally favorable route for cathodes with intact crystal structures. Among these methods, hydrothermal synthesis presents a promising balance between energy consumption and product quality. For severely degraded materials, full recycling via acid leaching is currently the most mature process, but it must be optimized to reduce waste and improve selectivity. Pyrometallurgy offers a robust alternative, but requires better gas cleaning and energy integration. Future research and industrial efforts should focus on, (1) developing intelligent, automated disassembly systems (e.g., robotic sorting and dismantling based on AI and 3D vision) to improve the purity and consistency of recovered black mass; (2) advancing novel, selective, and reusable leaching agents (e.g., deep eutectic solvents, functionalized ionic liquids) and integrating them with efficient electrochemical or membrane-based recovery systems; (3) enhancing the performance of regenerated materials through targeted doping (e.g., with Mn, N, B) and advanced coating technologies; (4) implementing holistic recovery processes that valorize all battery components, including the anode (graphite), electrolyte, and separator; and (5) designing future LFP batteries with greater structural modularity, standardized formats, and materials optimized for end-of-life repairability and recyclability. Addressing these challenges will pave an effective way for a truly circular and sustainable lithium-ion battery economy.

With the growing demand for high-energy-density, long-cycle-life, and low-cost batteries, the design and development of new electrodes/electrolytes become a focus of the energy storage field. However, the complex and variable material systems and the continuous evolution of the structure of active substances during the charge/discharge make their characterization an extremely challenge. As synchrotron radiation provides a high brightness, highly collimated, wide spectral range light source, high spatial/temporal/spectra resolution characterization methods can be developed and applied to the characterization of crystal structure, micro-structure, morphology, coordination environment, valence state of the electrodes/electrolytes as well as their distribution and evolution in the charge/discharge. In this review, we represent the latest progress on the synchrotron radiation based characterizations of electrodes/electrolytes of Li-ion batteries. This review describes the XRD, EXAFS, XCT and ATR-FTIR combined with various in-situ/ex-situ/operando environments. It is expected that the wide application of synchrotron radiation based characterization can prompt the development of key materials for next generation Li-ion batteries.

COFs demonstrate a significant potential as advanced sulfur host materials in Li-S batteries, effectively mitigating the polysulfide shuttle effect as a major bottleneck to commercialization through their tunable pore structures, high surface areas, and designable functional sites. This review systematically outlines the development of COF-based materials in Li-S battery cathodes, from early physical confinement strategies to recent advances involving heteroatom doping, multidimensional architectures, flexible frameworks, and conductive composites. These approaches can collectively enhance sulfur utilization, improve reaction kinetics, and increase cycling stability.

Despite these promising developments, several challenges remain for the practical application of COF-based cathodes. The key issues include the limited intrinsic conductivity of most COFs, difficulties in maintaining crystallinity during large-scale synthesis, insufficient chemical stability under prolonged cycling, and high manufacturing costs. Moreover, optimizing electrolyte/sulfur ratios and interface engineering between COFs and sulfur are critical for improving electrochemical performance.

Future research should prioritize 1) enhancing the electronic and ionic conductivity of COFs through structural design and hybridization with conductive substrates; 2) developing scalable and eco-friendly synthesis methods to facilitate commercial adoption; 3) designing COFs with high sulfur loading capacity and strong polysulfide adsorption; 4) improving chemical and mechanical stability under operating conditions; and 5) employing advanced in-situ characterization techniques to elucidate ion transport and reaction mechanisms. With continued innovation in material design and processing, COF-based sulfur hosts are expected to play a vital role in realizing high-energy, long-lasting, and commercially viable Li-S batteries.